Hey there!
I got a similar error too. Just created a ticket at the Pro-Support from NextGEN Gallery. I let you guys know when I get an answer. It looks like it blocks some scripts from other Plugins (SlideDeck 2 and BJ Lazy Load in my case).
Downgrading to an old version is pretty simple, just replace the plugin-folder with an older one. https://www.nextgen-gallery.com/how-to-rollback-a-version/
